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Bernie,
Now that is the kind of information I've been looking
for. What starter are you using in this test?
No one agreed on disagreed with my assumption
that the PC625 battery would be the one to choose if it weights less than the
PC680. According to the charts the PC625 has 3 minutes more reserve than the
PC680 but a little less in the cranking amps. Your measurements reinforce
my belief. Am I wrong?? Anyone have the weights of these batteries?
Wendell
Subject: [FlyRotary] Amps required to run engine & amp- hours
available
>
> One of my planned flyoff flight test is to shut the
alternator down and see how long I can fly before systems start to act up. Plan
on a second battery during flight test so that I can hopefully restart if
necessary or I will join the deadstick club over the airfield of my
choosing.
>
> I measured the amps required to keep the one pump,
the coils, the 4 injectors while running the engine this morning at about 3000
rpm. It measured at 7.8 amps. Also measured the amps to crank this morning (65 F
OAT): 142 amps.
>
> Had ordered a new Odessey PC625 since I had let
the 2+ year old one go flat over Christmas. (Yep left the av master on). Had to
shock it with 24 volts to get it to take a charge. Turns out, I can't measure
any difference of old vs. new during battery test. Hooked up 150 watts of 12
volt halogen bulbs which gives a draw of 12 amps at 12 volts. Man do these
things hold voltage until the end.It took 55 minutes to get to 11 volts and
dropped to 5 volts in another 15 minutes.
>
> Based on this, the
engine only should run the keep the airplane airborn for about 1:20 hours. How
about a sanity check Tracy, ED, etc; what did I miss??
>
> Bernie,
(DAR on Tuesday, engine behaving very nicely with new injector)
>
>
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>
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